H‐caldesmon expression in myofibroblastoma of the breast: evidence supporting the distinction from leiomyoma

Abstract

Our results, indicating that smooth muscle differentiation occurs in a minority of the myofibroblastoma cells exclusively in half of the analysed cases, support the separation of myofibroblastoma from leiomyoma. The detection of smooth muscle cells in breast myofibroblastoma is easily explained if we postulate its histogenesis from the CD34+ fibroblasts of mammary stroma capable of multidirectional mesenchymal differentiation, including smooth muscle. We recommend retention of the term myofibroblastoma for all the desmin-positive and/or alpha-smooth muscle actin-positive spindle cell tumours of the breast consistent with the previously well-established morphological criteria for such neoplasms, unless one is dealing with a typical leiomyoma easily recognizable at light microscopy.

Inflammatory myofibroblastic tumor and low-grade myofibroblastic sarcoma: a comparative study of clinicopathologic features and further observations on the immunohistochemical profile of myofibroblasts

“…In addition, calponin can be inconsistently encountered focally in a host of other spindle cell tumors, including malignant peripheral nerve sheath tumor, solitary fibrous tumor, dermatofibrosarcoma protuberans, fibrosarcoma, and carsinosarcoma [27,28]. Recently, h-caldesmon has been proposed as a useful marker for distinguishing smooth muscle tumors from myofibroblastic tumors, because h-caldesmon is negative in myofibroblastic lesions, such as fibromatosis [7,29] and nodular fasciitis [29]. Moreover, cases of IMT [7,9,11] and LGMS [6] were also reported to be negative for h-caldesmon.…”

“…Recently, h-caldesmon has been proposed as a useful marker for distinguishing smooth muscle tumors from myofibroblastic tumors, because h-caldesmon is negative in myofibroblastic lesions, such as fibromatosis [7,29] and nodular fasciitis [29]. Moreover, cases of IMT [7,9,11] and LGMS [6] were also reported to be negative for h-caldesmon. We have extended these observations, finding no h-caldesmon expression in all our cases of IMT and LGMS.…”

“…In benign and low-grade conditions, the currently accepted markers for identifying myofibroblasts are mainly myoid markers, including α-smooth muscle actin (α-SMA), muscle-specific actin (MSA), desmin, and calponin. As for the myoid marker h-caldesmon, 2 cases of LGMS were reported to lack the expression [6], but reported results in IMTs have been inconsistent [7][8][9][10][11]. α-SMA, MSA, hcaldesmon, and calponin are all associated with actin myofilaments [12] and hence not specific for myofibroblasts, although these markers are effectively used in the diagnosis when combined with cytomorphological and architectural features of myofibroblastic lesions.…”

h-Caldesmon, Calretinin, Estrogen Receptor, and Ber-EP4: A Useful Combination of Immunohistochemical Markers for Differentiating Epithelioid Peritoneal Mesothelioma From Serous Papillary Carcinoma of the Ovary

“…46 The clinical use of h-CD has been addressed mainly in differentiating smooth muscle tumors (eg, leiomyomas and leiomyosarcomas) from other soft tissue tumors with smooth muscle cell-like differentiation, including tumors of myofibroblastic and fibroblastic origin. 10,15,27,29,32,39,47,48 In addition, we recently demonstrated that h-CD is also a highly specific and sensitive positive marker of cells with mesothelial differentiation and therefore a new marker for the positive diagnosis of epithelioid mesothelioma. 14 D2-40 is a recently developed monoclonal antibody that reacts with a 40-kD oncofetal antigen, known as M2A antigen, expressed in fetal testis and in germ-cell tumors.…”

Myofibroblastoma of the breast: Case report and literature review

“…6-9). 18 The malignant variants of spindle cell presents typically greater cell density, marked nuclear pleomorphism, high mitotic activity with atypical mitotic figures. It has been extensively debated whether solitary fibrous tumor and myofibroblastoma of the breast should be considered as two distinct lesions.…”